Сучасні особливості циркуляційних умов формування термічного режиму на території України

Abstract

Дослідження присвячене сучасним особливостям циркуляції в тропосфері та стратосфері, які зумовлюють різкі підвищення і зниження температури повітря на території України. На основі статистичного аналізу повторюваності екстремальних значень середньої добової температури повітря й атмосферного тиску в січні, квітні, липні та жовтні виявлені деякі особливості стану стратосферних полярних вихорів, які впливають на тривалість та інтенсивність хвиль тепла і холоду, посилюючи, насамперед, їх екстремальність.

Исследование посвящено современным особенностям циркуляции в тропосфере и стратосфере, которые обуславливают резкие повышения и понижения температуры воздуха на территории Украины. На основании статистического анализа повторяемости экстремальных значений средней суточной температуры воздуха и атмосферного давления в январе, апреле, июле и октябре выявлены некоторые особенности состояния стратосферных полярных вихрей, которые влияют на длительность и интенсивность волн тепла и холода, усиливая, прежде всего, их экстремальность. Результаты исследования указывают на то, что современная изменение циркуляционных условий исследуемой территории, а именно перемещение влияния центров действия атмосферы, приводит к усилению экстремальности климатических условий, прежде всего, термического режима. Во все сезоны выявлены определенные особенности циркуляционных условий формирования волн тепла и холода разной интенсивности на территории Украины в конце 20 - начале 21 веков, указывает на необходимость их учета при разработке и составлении долгосрочных прогнозов температуры воздуха.

The research is devoted to modern features of circulation in the troposphere and stratosphere, which cause sharp increase and decrease in air temperature in Ukraine. The circulatory processes of the troposphere and stratosphere, as well as the factors that determine them, are complex, their interconnections are ambiguous and often asynchronous. At the same time, one can not but admit that modern atmospheric circulation changes also require a detailed study and analysis. Because modern features of circulation on the one hand have become one of the factors of changes in the modern climate, and on the other hand, they themselves have changed due to global climate change. In the proposed study, on the basis of statistical analysis of the repetition of extreme values of the average daily air temperature and atmospheric pressure in January, April, July and October for two periods corresponding to the end of the 20th and early 21st centuries, an attempt was made to find out the features of the state of stratospheric polar vortices affecting the duration and intensity of the waves of heat and cold in our country. The results of the study indicate that the current change in the circulation conditions of the study area, namely the movement of the influence of atmospheric centers, leads to increased extremes of climatic conditions, in particular, the thermal regime. Thus, in January, the increase in the frequency of cases with both extreme and extreme low atmospheric pressure indicates that the cyclones entering the territory of Ukraine from the North Atlantic have become more powerful, in the stratosphere they can be traced to the axis of the displaced center of the cyclonic vortex. Such deep cyclones bring warm air masses, formed over the waters of the ocean, and cause an extreme increase in air temperature. At the same time, the cold air of Arctic origin is actively flowing into the rear of such cyclones, as evidenced by the increasing recurrence of days with extremely low air temperatures. In April, the increase in the impact on the territory of Ukraine of the Azores peak is manifested in the region of increased atmospheric pressure of subtropical origin, which leads to an increase in the repetition of days with extremely high atmospheric pressure and a decrease in the frequency of cases with extremely low pressure. Such a transformation of the April marginal field leads to an increase in the frequency of cases of not too extreme increase in air temperature. In July, a very significant increase in the repetition of extremely high values of atmospheric pressure and high temperatures is recorded, which suggests that the summer stratospheric anticyclonic vortex is more stable at the present stage and cyclonic activity is not supported by altitude processes. In October, there is an increase in the repeatability of anticyclonic weather associated with the increased influence of the Azores peak, which leads to a significant increase in the frequency of positive anomalies of atmospheric pressure and air temperature. Taking into account the revealed features of the circulating conditions for the formation of heat and cold waves on the territory of Ukraine at the end of the 20th and early 21st centuries may be useful in the development and compilation of long-term air temperature forecasts.